Question

Male heterogametic, XX-XO type of sex determination is found in ___________.
(a) Butterflies
(b) Moth
(c) Grasshoppers
(d) Drosophila

Answer 1

Hint: The insects that show XX-XO type of sex determination are believed to be one of the ancient living group of chewing herbivorous insects. They are hemimetabolous insects, hence they do not undergo complete metamorphosis. They hatch from an egg into a nymph or a ‘hopper.’

Complete answer:
After going through the hint we can answer the question by saying that male heterogametic, XX-XO type of sex determination is found in grasshoppers.
Let's study sex determination in various animals in detail.
Through a number of studies, it was found that in a large number of insects the mechanism of sex determination is of the type XO. Here, in addition to the autosomes, all eggs bear an additional X-chromosome. Conversely, some of the sperms exhibit the X chromosome whereas some lack it. The eggs fertilized by sperms having an X-chromosome develop into female offspring while those fertilized by sperms that lack an X-chromosome become males. As this phenomenon involved X-chromosomes in the determination of sex, the chromosome was designated as ‘sex chromosome.’ All the chromosomes other than sex chromosomes are called ‘autosomes.’ A classic example of XO type of sex determination is seen in grasshoppers. In these insects, males exhibit only one X-chromosome besides the autosomes whereas females possess a pair of X chromosomes.
So, the correct answer is, (c) ‘Grasshoppers.’

Note: -In human beings and drosophila the males have one X and Y chromosome each, while females exhibit a pair of X chromosomes besides the autosomes.
-Moths and butterflies exhibit ZW type of sex determination. Here the ovum determines the gender of the offspring. Males show only one type of chromosome ZZ, while females present with heterogamety, showing two types of chromosomes ZW.